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UTEP professor develops Chagas vaccine

UTEP professor Dr. Igor C. Almeida, left and postdoctoral researcher Alexandre Marques showed a container of Trypanosoma cruzi parasites infecting host cells in a lab Wednesday at UTEP. Almeida has developed a vaccine that can protect against Chagas disease, a potentially fatal illness that affects millions of people around the world. (Victor Calzada / El Paso Times)

A University of Texas at El Paso professor has developed a vaccine that can protect against Chagas disease, a potentially fatal illness that affects millions of people around the world.

Dr. Igor C. Almeida, 52, a biological sciences professor, began his research 22 years ago in Brazil and reached the breakthrough stage after he arrived at UTEP.

Almeida said Alexandre F. Marques, 39, a postdoctoral researcher at UTEP and a collaborator in his lab, was instrumental in helping him develop the vaccine. Their work also helped put the university on the global map of medical research.

REPORTER

Diana Washington Valdez

"It is not every day that a person can change the medical textbooks so completely," said Stephen Aley, interim dean of UTEP's College of Science. "Because of the research of Dr. Igor Almeida, a frequently fatal disease of the Americas has become totally preventable. He is an outstanding example of how UTEP researchers impact millions of at-risk people in this region and throughout Central and South America."

Chagas disease is named after Carlos Chagas, a Brazilian doctor who discovered the disease in 1909, according to the US Centers for Disease Control and Prevention.

It is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by infected triatomines, insects known as "assassin bugs" or "kissing bugs." Chagas disease (T. cruzi infection) is also referred to as American trypanosomiasis.

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The turning point came after Almeida, who's been at UTEP since 2004, identified a particular type of sugar in the parasite that is foreign to the human body and causes the immune system to react and produce antibodies against it, which in turn kills the parasite.

After that, he and Marques created a vaccine that includes this sugar and administered it to special lab mice, which mimic human responses to the parasite.

The mice that received the vaccine had a 100 percent survival rate, and showed high levels of antibodies that could easily kill the parasite, Almeida said.

In other words, a substance that was extracted from the parasite was used to kill it.

Almeida said that some existing medicines currently used to treat Chagas disease can be toxic to patients, but that the new vaccine is completely safe.

"I am very excited about this development, which was built on 20 years worth of work," Almeida said. "These kind of breakthroughs do not happen overnight. We still have a lot of work ahead of us before the vaccine can be used on humans."

In 1997, Almeida co-invented the only test in the world that can be used to diagnose the disease and provide follow-up treatment. That test was part of a $3 million project underwritten by the Wellcome Trust to determine whether new and existing drugs can treat the disease reliably.

Almeida said the insects, which feed on blood, come out at night when their prey is asleep. The bugs transmit the infection through contaminated feces they drop on their victim while filling up on the victim's blood.

After the bite, the victim's affected area becomes itchy, causing victims to scratch the spot, which causes the insect's feces to move into the bite wound or into the mouth or eye.

The parasite then penetrates the bloodstream and infects cells throughout the body, particularly the heart and gastrointestinal system.

Humans can infect other humans through contaminated organ transplants and blood transfusions.

Pregnant women who are infected can transmit the disease to the unborn child. People also can be infected by ingesting contaminated foods and juices.

Chagas disease is prevalent in the Americas, mostly in northern Mexico, Central America and South America. In recent years, cases have been reported in Canada, the United States, Europe, Japan and Australia.

Regionally, Chagas has been detected in Tucson, Ariz.

A statement on the CDC's website states, "In the United States, Chagas disease is considered one of the neglected parasitic infections, a group of five parasitic diseases that have been targeted by CDC for public health action."

Almeida said an estimated 300,000 people in the United States are infected and may not know it.

For most people, the disease may start out with flu-like symptoms and not cause major problems for up to 80 percent of the infected population.

"However, an estimated 20 to 30 percent of infected people will develop debilitating and sometimes life-threatening medical problems over the course of their lives," the CDC said.

"We don't know why the 20 to 30 percent develop the major issues," Almeida said. "It might have something to do with their immune systems. All we know is that 80 percent that are infected are doing very well -- it's like being HIV-positive but not having AIDS."

The complications of chronic Chagas disease include:

Heart rhythm abnormalities that can lead to sudden death.

A dilated heart that fails to pump blood sufficiently well.

A dilated esophagus or colon, leading to difficulties with eating or passing stool.

Peter J. Hotez and Maria Elena Bottazzi, researchers at Baylor College of Medicine in Houston, along with several other academics, wrote an article about Chagas disease that PLOS Neglected Tropical Diseases, a respected journal, published May 29, 2012.

Hotez and Bottazzi are also principal investigators on another vaccine in development against Chagas disease. They said in the article that low-income people who lack access to adequate health care are less likely to get diagnosed and treated for the disease.

"Endemic Chagas disease has emerged as an important health disparity in the Americas. As a result, we face a situation in both Latin America and the U.S. that bears a resemblance to the early years of the HIV/AIDS pandemic," according to the PLOS article, titled "The New HIV/AIDS of the Americas."

UTEP's Almeida and Marques are from Brazil, where both obtained their undergraduate degrees in pharmacy.

Their graduate and doctoral work focused on microbiology and immunology.

Fernando Gonzalez, lead epidemiologist for the city of El Paso's Department of Public Health, said Chagas disease is not a reportable illness in Texas "due to its lack of prevalence."

After checking records of reports for the past six years, he said El Paso did not have a single case of Chagas disease that the department knows about.

Local public health officials might change their outlook based on Marques' experience last year.

Marques said he found an insect in West El Paso that is known to carry the disease and had it tested for the presence of the disease-causing parasite.

"We found out that it was infected with the disease," said Marques, who joined Almeida's lab at UTEP in 2007.

Almeida, the project's principal researcher, is awaiting funding to continue testing the breakthrough vaccine. He needs to conduct further clinical trials on animals and, later, trials on humans.

He said it costs from $800 million to $1 billion to bring an effective vaccine to market.

"I got into this because Chagas is very prevalent in Brazil, where I come from, and I wanted to work on an application that could be used to treat or prevent the disease. And some 20 years later, I've accomplished this lifetime goal."

Diana Washington Valdez may be reached at dvaldez@elpasotimes.com; 546-6140.

'Because of the research of Dr. Igor Almeida, a frequently fatal disease of the Americas has become totally preventable. He is an outstanding example of how UTEP researchers impact millions of at-risk people in this region and throughout Central and South America.'